<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        *{
            margin: 0px;
            padding: 0px;
        }
        .box{
            width: 500px;
            height: 500px;
            background-color: gold;
            display: flex;
            justify-content: center;
            align-items: center;
        }
        .content{
            width: 200px;
            height: 200px;
            background-color: skyblue;
        }
    </style>
</head>
<body>
    <div class="box">
        <div class="content"></div>
    </div>
</body>
</html>